On the basis of a 51-year statistical analysis of reanalysis data, we propose for the first time that the positive phase of the Western Pacific (WP) pattern in the winter is linked to the negative phase of the North Atlantic Oscillation (NAO) in the previous winter, and vice versa. We show that there are two possible mechanisms responsible for this interannual remote linkage. One is an Arctic mechanism. Extensive Arctic sea ice in the summer after a negative NAO acts as a bridge to the positive phase of the WP in the next winter. The other mechanism involves the tropics. An El Niño occurrence after a negative winter NAO acts as another bridge to the positive phase of the WP in the following winter. The timescale of the Arctic route is nearly decadal, whereas that of the tropical route is about 3–5 years. The tropical mechanism indicates that the NAO remotely excites an El Niño in the second half of the following year. A process perhaps responsible for the El Niño occurrence was investigated statistically. A negative NAO in the winter increases Eurasian snow cover. This anomalous snow cover then intensifies the cold air outbreak from Asia to the western tropical Pacific. This outbreak can intensify the westerly wind burst and excite El Niño in the following year. We suggest that the phase of the NAO in the winter could be a predictor of the WP in the following year.
Difficult to control winter annual grasses that have been used to produce forage, especially Italian ryegrass (Lolium multiflorum Lam.) and feral rye (Secale cereale L.), have invaded Oklahoma fields traditionally used to produce continuous winter wheat (Triticum aestivum L.). This study was conducted to determine whether a winter canola (Brassica napus L.)-winter wheat crop rotation could compete economically with continuous winter wheat. The effects of seven herbicide treatments for continuous wheat and 24 herbicide treatments for the canola-wheat rotations were analyzed during a rotation cycle at four Oklahoma locations. Enterprise budgets were prepared to enable economic comparisons across production systems and treatments. Wheat yields in the second year of the canola-wheat rotations were significantly (P < 0.05) greater than wheat yields in the second year of continuous wheat across all four locations (10, 11, 15, and 22%). Based on the historical relationship between wheat and canola prices, and a wheat price of US$0.21 kg(-1) and a canola price of US$0.40 kg-1, for the three sites for which net returns could be pooled across herbicide treatments, net returns from the canola-wheat rotation (US$197, US$123, and US$24 ha(-1) yr(-1)) were significantly (P < 0.05) greater than net returns from continuous wheat (-US$46, -US$118, and -US$48 ha(-1)yr(-1)). Based on historical price relationships and the yields produced in the trials, a winter canola-winter wheat crop rotation may improve net returns relative to continuous winter wheat for Oklahoma fields infested with Italian ryegrass and feral rye.
This paper describes a series of winter wheat - winter barley disomic addition lines developed from hybrids between winter wheat line Triticum aestivum L. `Martonvásári 9 kr1' and the German 2-rowed winter barley cultivar Hordeum vulgare L. `Igri'. The barley chromosomes in a wheat background were identified from the fluorescent in situ hybridization (FISH) patterns obtained with various combinations of repetitive DNA probes: GAA-HvT01 and pTa71-HvT01. The disomic addition lines 2H, 3H, and 4H and the 1HS isochromosome were identified on the basis of a 2-colour FISH with the DNA probe pairs GAA-pAs1, GAA-HvT01, and pTa71-HvT01. Genomic in situ hybridization was used to confirm the presence of the barley chromosomes in the wheat genome. The identification of the barley chromosomes in the addition lines was further confirmed with simple-sequence repeat markers. The addition lines were also characterized morphologically.Cet article décrit une série de lignées d'addition disomiques entre le blé d'automne et l'orge d'automne développées à partir d'hybrides entre le blé d'automne `Martonvásári 9 kr1' et l'orge d'automne à deux rangs allemande `Igri'. Les chromosomes de l'orge au sein du génome du blé ont été identifiés sur la base d'hybridations in situ en fluorescence (FISH) réalisées avec des sondes d'ADN répétitifs: GAA-HvT01 et pTa71-HvT01. Les lignées d'addition disomiques 2H, 3H, 4H et l'isochromosome 1HS ont été identifiés par FISH bicolore avec les paires de sondes GAA-pAs1, GAA-HvT01 et pTa71-HvT01. Des hybridations génomiques in situ (GISH) ont été pratiquées pour confirmer la présence des chromosomes d'orge dans le génome du blé. L'identité des chromosomes d'orge au sein des lignées d'addition a été confirmée à nouveau à l'aide de marqueurs SSR. Les lignées d'addition ont également été caractérisées sur le plan morphologique.
In this paper, the winter indoor thermal environment of dwellings in China's Hot Summer – Cold Winter (HSCW) climate region has been investigated by on-site measurement. And the driving forces of the heating requirements of residents in HSCW area has been scrutinized by heteroskedasticity-robust Ordinary Least Square analysis. It is found that in HSCW area, the average internal temperature is 13.5 °C for the living room and 12.7 °C for the bedroom, leading to an uncomfortable indoor thermal environment, markedly colder than that in the UK, which has similar winter climate. Through the investigation of the occupant heating behavior, it was found that domestic heating is operated part-time-part-space and triggered by both time and temperature in the HSCW area. 10 °C is found to be the lowest acceptable internal temperature without heating. The poor indoor thermal environment observed in HSCW area is mainly due to the short heating operation duration (averagely 1.9 h per day for the living room and 1.4 h for the bedroom). Income, presence of child, heating system and thermal experience markedly influence occupants' heating requirements. However, the education is not a statistically significant factor. The rebound effect is observed in HSCW area when analyzing the effects of building energy efficiency on indoor thermal environment.
The project “Winter Model” started at the beginning of the 2000s. The idea was to try and predict the consequences of different winter maintenance strategies and to calculate the associated socio-economic costs. It is now possible to calculate and validate the impact that different winter maintenance measures have on road users, road authorities and local communities. This paper contains results of the first complete Winter Model calculations using existing conditions. Comparisons with different road classification standards have been carried out in order to determine the effect they have on socio-economic costs. Road classification standards dictate how much snow should fall before a maintenance action is initiated and how long it should take until the action is completed. Socio-economic costs increased for all comparisons when reductions in the classification standard were applied. As an example of how costs can vary: the scenario is a salted road using a combined plough and salt spreader where the allowed time to complete the action is 4 h that is changed to an unsalted road with an allowed time to complete the action of 5 h. Both scenarios have an action start criteria of 2 cm deep snow, and an annual average daily traffic flow of 2000. Comparison results show that the change from salted to unsalted road saves the most cost due to a reduction in salt use and required actions. However, the increased time to complete the action will result in slightly longer travel times and accident costs will increase by 24.2%. The extended action hour affect fuel consumption in a positive way, for example, consumption decreases slightly due to driving more often at lower speeds on unclear roads. By lowering the road classification standard like in this example, total socio-economic costs increased by 3.5%.
Experiments on the Rothamsted and Woburn Experimental Farms studied the effects on take‐all of different break crops and of set‐aside/conservation covers that interrupted sequences of winter wheat. There was no evidence for different effects on take‐all of the break crops per se but the presence of volunteers, in crops of oilseed rape, increased the amounts of take‐all in the following wheat. Severity of take‐all was closely related to the numbers of volunteers in the preceding break crops and covers, and was affected by the date of their destruction. Early destruction of set‐aside/conservation covers was usually effective in preventing damaging take‐all in the following wheat except, sometimes, when populations of volunteers were very large. The experiments were not designed to test the effects of sowing dates but different amounts of take‐all in the first wheats after breaks or covers apparently affected the severity of take‐all in the following (second) wheats only where the latter were relatively late sown. In earlier‐sown second wheats, take‐all was consistently severe and unrelated to the severity of the disease in the preceding (first) wheats. Results from two very simple experiments suggested that substituting set‐aside/conservation covers for winter wheat, for 1 year only, did not seriously interfere with the development of take‐all disease or with the development or maintenance of take‐all decline (TAD). With further research, it might be possible for growers wishing to exploit TAD to incorporate set‐aside/conservation covers into their cropping strategies, and especially to avoid the worst effects of the disease on grain yield during the early stages of epidemics.